The Aim of the Flow Cytometry Core is to provide access to state-of-the art flow cytometry for all the members of the Oklahoma Anthrax Group (U19). The Flow Cytometry Core has two high speed fluorescence activated cell sorters (Dako-Cytomation MoFlo and BD FACSAria) and three analyzers (FACScan, FACSCalibur and LSRll analyzer, all from BD). Dr. Linda Thompson, who is an expert in multicolor analysis and sorting of human lymphocytes, will serve as Core Director and technical assistance will be provided by Mr. Jacob Bass and Dr. Diana Hamilton. Funds for the purchase of monoclonal antibodies and user fees will be provided to all COBRE participants. All four research projects and the Human Antibody Core depend upon flow cytometry to accomplish their scientific goals. Thus, this Core will be heavily used and is critical for the success of the Oklahoma Anthrax Group.